Conduit flow metering kit, method and apparatus

ABSTRACT

A flow meter apparatus comprising: at least two magnets polarized in substantially opposite directions, mechanically coupled to a mechanical element mounted in a flow conduit and movable by a substance flowing through the flow conduit, for imparting movement from the mechanical element to the magnets, and at least two magnetic field sensors, each of the sensors deployed in a respective position next to the magnets, configured to sense a direction of a magnetic field in the position and to generate a signal indicative of the direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 13/993,902,which is the U.S. national phase of International Application No.PCT/IB2011/050301, filed Jan. 24, 2011; each of which is herebyincorporated in its entirety including all tables, figures, and claims.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to the measurement of gas or liquid flow,and more particularly, but not exclusively, to a flow meter apparatus,for measurement of substance (say gas or liquid) flow through a conduit.

The measurement of liquid or gas flow under pressure in enclosed pipeshas historically been performed through the use of mechanical flowmeters.

Typically, in the mechanical flow meters, a first mechanism has movingparts which move upon interaction with a gas or a fluid flowing througha pipe, and the movement of the parts is mechanically transmitted tomoving parts of a second mechanism used to register the amount of wateror gas flowing through the pipe.

For example, piston meters, also known as rotary piston or semi-positivedisplacement meters, operate on the principle of a piston rotatingwithin a chamber of known volume. For each rotation, an amount of waterpasses through the piston chamber. As the piston rotates, a needle dialand an odometer type display are advanced.

A turbine flow meter translates the mechanical action of the turbinerotating in a liquid flow around an axis into a user-readable rate offlow.

The turbine's wheel is set in the path of a fluid stream. The flowingfluid impinges the wheel's blades, imparting a force to the bladessurfaces and setting the wheel in motion. When a steady rotation speedis reached, the rotation speed is proportional to fluid velocity.

Turbine flow meters are used for the measurement of both gas and liquidflow.

With turbine meters, the flow direction is generally straight throughthe meter, allowing for higher flow rates and less pressure loss thandisplacement-type meters.

Turbine meters have become the meters of choice for large commercialusers, fire protection, and as master meters for water distributionsystems.

A woltmann meter comprises a rotor with helical blades inserted axiallyin the flow, much like a ducted fan. Woltmann meters may be considered atype of turbine flow meter. Woltmann meters are commonly referred to ashelix meters, and are popular at larger sizes.

A nutating disk meter is probably the most commonly used meter formeasuring water supply.

With a nutating disk meter, the substance, most commonly water, entersin one side of the meter and strikes a nutating disk, which iseccentrically mounted. The disk must then nutate about the verticalaxis, since the bottom and the top of the disk remain in contact with amounting chamber. A partition separates the inlet and outlet chambers.As the disk nutates, it gives direct indication of the volume of theliquid that has passed through the meter as volumetric flow is indicatedby a gearing and register arrangement, which is connected to the disk.

Some mechanical flow meters are rather pressure-based.

Pressure-based flow meters typically rely on Bernoulli's principle,either by measuring the differential pressure within a constriction, orby measuring static and stagnation pressures to derive the dynamicpressure.

For example, a Venturi meter constricts the flow in some fashion, andpressure sensors measure the differential pressure before and within theconstriction. This method is widely used to measure flow rate in thetransmission of gas through pipelines, and has been used since RomanEmpire times.

Optical flow meters use light to determine flow rate.

In one example, small particles which accompany natural and industrialgases pass through two laser beams focused in a pipe by illuminatingoptics. Laser light is scattered when a particle crosses the first beam.The detecting optics collects scattered light on a photo detector, whichthen generates a pulse signal. If the same particle crosses the secondbeam, the detecting optics collect scattered light on a second photodetector, which converts the incoming light into a second electricalpulse. By measuring the time interval between the two pulses, the gasvelocity may be calculated.

Another currently used flow meter is a magnetic flow meter in which amagnetic field is applied to a metering tube, which results in apotential difference proportional to the flow velocity perpendicular tothe flux lines. The physical principle at work is Faraday's law ofelectromagnetic induction. The magnetic flow meter requires a conductingfluid, e.g. water, and an electrical insulating pipe surface, e.g. arubber lined nonmagnetic steel tube.

Ultrasonic flow meters measure the difference of transit time ofultrasonic pulses propagating in and against flow direction. This timedifference is a measure for the average velocity of the fluid along thepath of the ultrasonic beam. By using the absolute transit times boththe averaged fluid velocity and the speed of sound can be calculated, asknown in the art.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided aflow meter apparatus comprising: at least two magnets polarized insubstantially opposite directions, mechanically coupled to a mechanicalelement mounted in a flow conduit and movable by a substance flowingthrough the flow conduit, for imparting movement from the mechanicalelement to the magnets, and at least two magnetic field sensors, each ofthe sensors deployed in a respective position next to the magnets,configured to sense a direction of a magnetic field in the position andto generate a signal indicative of the direction.

Optionally, the flow meter apparatus further comprises a processor, incommunication with the magnetic field sensors, configured to calculate aparameter characterizing the flowing of the substance through theconduit, using changes in the generated signals indicative of thedirections.

According to a second aspect of the present invention, there is provideda method for flow metering, comprising the steps of: a) installing atleast two magnets polarized in substantially opposite directions,mechanically coupled to a mechanical element mounted in a flow conduitand movable by a substance flowing through the flow conduit, forimparting movement from the mechanical element to the magnets, b)deploying at least two magnetic field sensors, each sensor beingdeployed in a respective position next to the magnets, and c) sensing adirection of a magnetic field in each of the positions, using the sensordeployed in the position.

Optionally, the method further comprises a step of calculating aparameter characterizing the flowing of the substance through theconduit, using changes in the sensed directions.

According to a third aspect of the present invention, there is provideda flow meter kit comprising: a processor, configured to communicate withat least two magnetic field sensors and calculate a parametercharacterizing flowing of a substance through a flow conduit, usingchanges in a signal generated by each respective one of the sensors, thesignal being indicative of a direction of a magnetic field in positionof the sensor, the magnetic field being produced by at least two magnetspolarized in substantially opposite directions and mechanically coupledto a mechanical element mounted in the flow conduit and movable by thesubstance flowing through the flow conduit, for imparting movement fromthe mechanical element to the magnets.

Optionally, the kit further comprises the magnets, for mechanicalcoupling to the mechanical element, with polarity in substantiallyopposite directions.

Optionally, the kit further comprises the sensors, for deployment in thepositions, in a predefined spatial relation to the magnets.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. The materials, methods, andexamples provided herein are illustrative only and not intended to belimiting.

Implementation of the method and system of the present inventioninvolves performing or completing certain selected tasks or stepsmanually, automatically, or a combination thereof.

Moreover, according to actual instrumentation and equipment of preferredembodiments of the method and system of the present invention, severalselected steps could be implemented by hardware or by software on anyoperating system of any firmware or a combination thereof.

For example, as hardware, selected steps of the invention could beimplemented as a chip or a circuit. As software, selected steps of theinvention could be implemented as a plurality of software instructionsbeing executed by a computer using any suitable operating system. In anycase, selected steps of the method and system of the invention could bedescribed as being performed by a data processor, such as a computingplatform for executing a plurality of instructions.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, withreference to the accompanying drawings. With specific reference now tothe drawings in detail, it is stressed that the particulars shown are byway of example and for purposes of illustrative discussion of thepreferred embodiments of the present invention only, and are presentedin order to provide what is believed to be the most useful and readilyunderstood description of the principles and conceptual aspects of theinvention. The description taken with the drawings making apparent tothose skilled in the art how the several forms of the invention may beembodied in practice.

In the drawings:

FIG. 1 is a block diagram schematically illustrating a first flow meterapparatus, according to an exemplary embodiment of the presentinvention.

FIG. 2 is a block diagram schematically illustrating a second flow meterapparatus, according to an exemplary embodiment of the presentinvention.

FIG. 3A is a block diagram schematically illustrating a third flow meterapparatus, according to an exemplary embodiment of the presentinvention.

FIG. 3B is a first block diagram schematically illustrating the thirdflow meter apparatus, according to an exemplary embodiment of thepresent invention, from a top view.

FIG. 3C is a second block diagram schematically illustrating the thirdflow meter apparatus, according to an exemplary embodiment of thepresent invention, from a top view.

FIG. 3D is a third block diagram schematically illustrating the thirdflow meter apparatus, according to an exemplary embodiment of thepresent invention, from a top view.

FIG. 4A is a block diagram schematically illustrating a fourth flowmeter apparatus, according to an exemplary embodiment of the presentinvention.

FIG. 4B is block diagram schematically illustrating the fourth flowmeter apparatus, according to an exemplary embodiment of the presentinvention, from a top view.

FIG. 5A is a block diagram schematically illustrating an exemplary pairof opposite magnets, in a top view, according to an exemplary embodimentof the present invention.

FIG. 5B is a block diagram schematically illustrating an exemplary pairof opposite magnets, in a cross-sectional view, according to anexemplary embodiment of the present invention.

FIG. 6 is a flowchart schematically illustrating a flow metering method,according to an exemplary embodiment of the present invention.

FIG. 7 is a graph illustrating concerted changes in a sensor signal andin a magnetic field, according to an exemplary embodiment of the presentinvention.

FIG. 8 is a block diagram schematically illustrating a flow meter kit,according to an exemplary embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present embodiments comprise a flow meter apparatus, a method forflow metering, and a flow meter kit.

A flow meter apparatus, according to an exemplary embodiment of thepresent invention, includes two or more magnets polarized in oppositedirections (say one or more magnets with a north pole up and a southpole down, and one or more magnets with a south pole up and a north poledown).

The magnets of opposite polarization are mechanically coupled to amechanical element mounted in a flow conduit, say a mechanical meteringdevice mounted in a water pipe or in a gas pipe, for imparting movementfrom the mechanical element to the magnets.

Upon flowing of a substance (say water) through the conduit, themechanical element moves and imparts the movement to the magnets, say alateral movement or a rotational movement or, as described in furtherdetail hereinbelow.

The exemplary flow meter apparatus further includes two or more magneticfield sensors deployed in points next to the magnets, say in acompartment positioned about twelve millimeters above a plane in whichthe magnets move in concert with the mechanical element, as described infurther detail hereinbelow.

Each of the sensors senses the direction of a magnetic field in thepoint in which the sensor is deployed, and generates a signal indicativeof the direction.

The strength and direction of a magnetic field in each of the pointsdepend on the instant positions of the two (or more) magnets, and variesas the magnets move in concert with the mechanical element (say rotateor move latterly).

Consequently, a parameter which characterizes the flow of substancethrough the pipe may be calculated, according to changes in the signalsgenerated by the sensors, as described in further detail hereinbelow.

The parameter may include but is not limited to velocity, volume (orconsumption), etc. The parameter may be used utilized for displayingincremental tallying and reckoning data, as described in further detailhereinbelow.

The principles and operation of an apparatus according to the presentinvention may be better understood with reference to the drawings andaccompanying description.

Before explaining at least one embodiment of the invention in detail, itis to be understood that the invention is not limited in its applicationto the details of construction and the arrangement of the components setforth in the following description or illustrated in the drawings.

The invention is capable of other embodiments or of being practiced orcarried out in various ways. Also, it is to be understood that thephraseology and terminology employed herein is for the purpose ofdescription and should not be regarded as limiting.

Reference is now made to FIG. 1, which is a block diagram schematicallyillustrating a first flow meter apparatus, according to an exemplaryembodiment of the present invention.

A flow meter apparatus 1000 according to an exemplary embodiment of thepresent invention, includes two or more magnets 111, 112, say permanentmagnets such as corrosion protected magnets of grade N45,electromagnets, etc. as known in the art.

The magnets 111, 112 are polarized in opposite (or nearly opposite)directions, say one magnet 111 with a south pole up and a north poledown and one magnet 112 with a north pole up and a south pole down.

Optionally, the magnets 111, 112 comprise one or more paired sets (i.e.2, 4, etc.) of magnets arranged in alternating polarization directions,to form a linear array, a tubular array such as a ring, etc., asdescribed in further detail hereinbelow.

The magnets 111, 112 are mechanically coupled to a mechanical element115 mounted in a flow conduit 116 (say a compartment of the apparatus1000, through which the substance flows), as described in further detailhereinbelow.

For example, the magnets 111, 112 may be affixed to the mechanicalelement using glue, fasteners (say screws), etc., as described infurther detail hereinbelow.

The mechanical element 115 is moved by a substance, as the substanceflows through the flow conduit 116, as known in the art.

The movement of the mechanical element may be, but is not limited to: arotational movement, a lateral movement, an irregular movement, etc., asknown in the art.

The mechanical coupling of the magnets 111, 112 to the mechanicalelement 115, allows impartment of the movement of the element 115 fromthe element 115 to the magnets 111, 112.

In one example, and similarly to elements of many currently usedmechanical metering devices, the mechanical element 115 is a rotationalelement such as a wheel connected to a rotatable shaft, say a rotor withrotor vanes extending radially at an angle of inclination with therotor's axis (i.e. with the rotatable shaft).

The mechanical element 115 is set in path of a material (say a fluid ora gas) which flows through the flow conduit 116.

As the material flows through the conduit 116, the material impinges onthe vanes and imparts a force to the vanes' surfaces, thus setting therotor in rotational motion, as known in the art. Consequently, themagnets 111, 112 mechanically coupled to the mechanical element 115,rotate with the wheel 115.

The mechanical element 115 may also have any of other known in the artforms, usable for generation of movement by a material which flowsthrough a flow conduit, as currently used for mechanically measuringflow, such as turbines of various designs, Woltmann meters,pressure-based meters, etc.

The apparatus 1000 further includes two or more magnetic field sensors121, 122.

Each of the sensors is deployed in a respective position next to themagnets 111, 112, say in a distance of 1 to 20 millimeter from themagnets 111, 112. The sensor senses a direction of a magnetic field inthe position, and generates a signal indicative of the direction.

Optionally, the magnets 111, 112 are mounted on the mechanical element115 (say the rotor of the example provided hereinabove) and rotatesimultaneously with the mechanical element 115. Consequently, thedirection of the magnetic field sensed by each of the sensors 121, 122,which depends on each sensor's position relative to each of the magnets111,112, alternates in concert with rotation of the magnets 111, 112, asdescribed in further detail hereinbelow.

Optionally, the flow meter apparatus 1000 further includes a processor130, in communication with the magnetic field sensors 121, 122.

Optionally, the processor 130 communicates with the sensors 121, 122through a printed circuit, as known in the art.

Optionally, the processor 130 is embedded in an electric circuit (say ona digital processing board as known in the art).

The processor 130 calculates a parameter which characterizes the flowingof the substance through the conduit 116, using changes in the signalsgenerated by the sensors 121, 122.

The signals generated by the sensors 121,122 are indicative of thedirections of the magnetic fields.

Consequently, the changes in the signals are indicative of changes inthe directions of the magnetic fields, as described in further detailhereinbelow.

The calculated parameter may include, but is not limited to: velocity offlowing of the substance through the conduit 116, volume of substancewhich flows through the conduit 116, direction of flow of the substancethrough the conduit 116, etc.

Optionally, the processor 130 controls the sensors 121, 122, bydynamically adjusting a frequency rate in which each of the sensors 121,122 samples the direction and strength of magnetic field in the sensor'sposition, and re-generates (i.e. updates) the signal.

In one example, every two seconds, the processor 130 instructs thesensors 121, 122 to sample the magnetic field. When the velocity ofsubstance flow increases, the processor 130 increases the frequency inwhich the processor 130 instructs the sensors to sample the magneticfield.

By adjusting the frequency of the sampling, the processor 130 may saveelectric power consumption by the sensors 121, 122, and extend thesensors' life expectancy, as described in further detail hereinbelow.

Optionally, each of the magnetic field sensors 121, 122, generates afirst signal when the magnetic field is a magnetic field of a firstdirection, with an intensity which is greater than a first threshold.The sensor's signal remains the same (i.e. the generated first signal),until the magnetic field turns into a magnetic field of an oppositedirection, with an intensity which is greater than a second threshold,as described in further detail hereinbelow.

In one example, each of the sensors 121, 122, is a Hall-effect digitallatch connected to the processor 130 through a channel of an electriccircuit board on which the processor 130 is implemented.

The latch switches on only when the latch senses a south magnetic fieldof an intensity greater than a first threshold (as predefined by thelatch vendor), in which case, the latch transmits a positive signal (saya ‘1’ bit) to the processor 130.

In the example, the switched on Hall-effect digital latch switches offonly when the magnetic field turns into a north magnetic field of anintensity greater than a second threshold (as predefined by the latchvendor), as described in further detail hereinbelow. That is to say thatonce turned on, the latch remains turned on and the signal remainspositive, until the latch senses a north magnetic field of intensitygreater than the second threshold.

When the latch switches off, the latch transmits a negative signal (saya ‘0’ bit) to the processor 130, as described in further detailhereinbelow.

The processor 130 uses the changes (also referred to hereinbelow asinterrupts) in the signals, to calculate the parameter whichcharacterizes the flow, as described in further detail hereinbelow.

The two thresholds may be the same (only with a magnetic field inopposite direction), as described in further detail hereinbelow.

A carefully selected distribution of the sensors may provide for flowmeasurement in an accurate and energy efficient manner.

Optionally, the sensors are distributed in an asymmetric manner, over acircle in which the magnets 111, 112 rotate, as described in furtherdetail for the examples provided hereinbelow.

In a first example, the magnets 111, 112 rotate in a circle, in a planebelow the magnetic field sensors 121, 122.

In the first example, the magnetic field include 121,122 two sensors,and each of the sensors 121, 122 is deployed in a respective positionover a point in the circle's circumference. The points form an angle ofabout ninety degrees with an axis of the magnets' rotation, as describedin further detail hereinbelow.

As the magnets 111, 112 rotate below the sensors 121, 122, the magneticfield sensed by each of the sensors 121, 122 alternates betweendifferent magnetic polarity directions, as described in further detailhereinbelow.

In a second example, the magnets 111, 112 also rotate in a circle in aplane below the magnetic field sensors.

However, in the second example, the magnetic field sensors comprisethree sensors, and each of the sensors 121, 122 is deployed in arespective position over a point in the circle's circumference. Each twoadjacent ones of the points form an angle of about sixty degrees with anaxis of rotation of the magnets 111, 112, as described in further detailhereinbelow.

Optionally, the processor 130, as well the magnets 111, 112 and thesensors 121, 122 may be removed from the apparatus 1000, for repair,routine maintenance, replacement, etc.

Optionally, the flow meter apparatus 1000 further includes a powersource (not shown), such as a small battery, which provides power to thesensors 121, 122 and the processor 130, as known in the art.

Optionally, the flow meter apparatus 1000 further includes a display,say a small Liquid Crystal Display (LCD), connected to the processor130.

The processor 130 may present the calculated or incremental tallying andreckoning data based on the parameter on the display, as known in theart.

The processor 130 may recalculate the parameters on a periodic basis,say every few seconds or each time one of the sensor's signal changes,and present the recalculated parameter on the display.

Optionally, the apparatus 1000 further includes a modem (say a radiofrequency modem or an internet modem). The processor 130 uses the modem,for communicating the calculated parameter to a remote party, say to acomputer in remote communication with the apparatus 1000.

Reference is now made to FIG. 2, which is a block diagram schematicallyillustrating a second flow meter apparatus, according to an exemplaryembodiment of the present invention.

An exemplary flow meter apparatus 2000 is used as a flow meter formeasuring liquid flow through a pipeline 201.

The apparatus 2000 is installed in the pipeline 201, say in a pipe whichsupplies water to an apartment, in a gas pipeline, etc.

The flow meter apparatus 2000 includes two magnets 210.

The magnets 210 are polarized in substantially opposite directions, sayone magnet with a north pole up and a south pole down and one magnetwith a south pole up and a north pole down.

More specifically, the magnets 210 are installed in a flow conduit 216which forms a lower part of the apparatus 2000, in mechanical couplingto a wheel 215 (say a rotor). One magnet is installed with a north poleup and another magnet is installed with a south pole up.

The magnets 210 are mounted on a rotational shaft 218 connected to thewheel 215. The magnets 210 rotate simultaneously with the wheel 215 andthe shaft 218, as the fluid or gas flows through the flow conduit 216 ofthe apparatus 2000 and sets the wheel 215 in rotational movement, asdescribed in further detail hereinabove.

The apparatus 2000 further includes two magnetic field sensors 221, 222.

Each of the sensors is deployed in a respective position next to themagnets 210, say in a position 1 to 20 millimeter above the magnets 210.The sensor senses a direction of a magnetic field in the position, andgenerates a signal indicative of the direction.

As the magnets 210 rotate simultaneously with the wheel 215 and theshaft 218, the direction of the magnetic field sensed by each of thesensors 221, 222, which depends on each sensor's position relative toeach of the magnets 210, alternates in concert with the rotation of themagnets 210, as described in further detail hereinbelow.

The flow meter apparatus 2000 further includes a processor 230, say aprocessor 230 implemented on an electric circuit, as described infurther detail hereinabove.

The processor 230 communicates with the sensors 221, 222, for receivingthe signals generated by sensors 221, 222, and calculates a parameterwhich characterizes the flowing of the fluid through the conduit 216,using changes in the signal generated by the first sensor 221 andchanges in the signal generated by the second sensor 222.

The signals generated by the sensors 221, 222 are indicative of thedirections of the magnetic field in each sensor's position.Consequently, the changes in the signals are indicative of changes indirection of the magnetic fields in the position, which occur as thewheel 215 rotates and the magnets 210 rotate with the wheel 215.

That is to say that the changes in the signal reflect the rotationalmovement of the wheel 315, and are thus useful for calculating theparameter characterizing the flow of the fluid through the conduit, asdescribed in further detail hereinbelow.

The calculated parameter may include, but is not limited to: velocity offlowing of the substance through the conduit, volume of the substancewhich flows through the conduit, direction of flow of the substancethrough the conduit, etc.

Reference is now made to FIG. 3A, which is a block diagram schematicallyillustrating a third flow meter apparatus, according to an exemplaryembodiment of the present invention.

An exemplary flow meter apparatus 3000 includes two magnets 311, 312which from a ring. Each magnet is shaped as a half of the ring, asdescribed in further detail and illustrated using FIGS. 5A and 5Bhereinbelow.

The two magnets 311, 312 are similar in magnetic field strength anddimensions.

However, the two magnets 311, 312 are polarized in substantiallyopposite directions. More specifically, one magnet 311 is installed witha north pole up and a south pole down, and one magnet 312 is installedwith a south pole up and a north pole down.

The magnets 311, 312 are mechanically coupled to a mechanical element315 mounted in a flow conduit. The mechanical element 315 is movable bya substance flowing through the flow conduit, say water or gas, as knownin the art.

The mechanical coupling of the magnets 311, 312 to the element 315allows impartment of the movement from the mechanical element 315 to themagnets 311, 312, as described in further detail hereinabove.

Optionally, the mechanical element 315 is a rotational element such as awheel connected to a rotatable shaft 318, as described in further detailhereinabove.

The mechanical element 315 is set in path of the substance which flowsthrough the flow conduit. As the substance flows through the conduit,the wheel is set in rotational motion, as described in further detailhereinabove.

Consequently, the magnets 311, 312 mechanically coupled to themechanical element 315 (i.e. the wheel), rotate with the wheel 315.

The apparatus 1000 further includes two magnetic field sensors 321, 322.

Each of the sensors 321, 322 is deployed in a respective position over apoint in circumference of the circle on which the magnets 311, 312rotate. The points form an angle of about ninety degrees with an axis(i.e. with the shaft 318) of the magnets' rotation, as described infurther detail hereinbelow.

The sensor senses a direction of a magnetic field in the position, andgenerates a signal indicative of the direction.

The direction of the magnetic field sensed by each of the sensors 321,322, depends on each sensor's position in relation to each of themagnets 311,312.

As the substance flows through the conduit, the magnets 311, 312 rotatewith the wheel 315, and the direction of the magnetic field sensed byeach of the sensors 321, 322, alternates in concert with the rotation ofthe magnets 311, 312, as described in further detail hereinbelow.

Reference is now made to FIG. 3B, which is a block diagram schematicallyillustrating the third flow meter apparatus 3000, from a top view.

As schematically illustrated using FIG. 3B, each of the sensors 321, 322is deployed in a respective position over a point in circumference ofthe circle, on which the magnets 311, 312 rotate. The points form anangle of about ninety degrees with an axis of the magnets' rotation, asdescribed in further detail hereinbelow.

As the magnets 311, 312 rotate below the sensors 321, 322, the magneticfield sensed by each of the sensors 321, 322 alternates betweendifferent magnetic polarity directions.

For example, when the rotation of the magnets brings the magnets 311,312 into the positions in FIG. 3B, a first sensor 321 senses a magneticfield which lacks a strong enough direction. The magnetic field lacks astrong enough direction because the sensor 321 is in a position over amidpoint between the two magnets 311, 312. In the position, the magneticfield of the magnet 311 with a north pole up significantly offsets themagnetic field of the magnet 312 with a south pole up, thus preventing astrong enough magnetic field in both polarization directions.

By contrast, the second sensor 322 is in a position over the magnet 312with a south pole up. Consequently, the second sensor 322 senses amagnetic field which has a strong intensity in one direction, namely thesouth.

As the magnets 311, 312 rotate, the magnetic field sensed by each of thesensors 321, 322 alternates between different magnetic polaritydirections, with a ninety degrees phase difference between the sensors321, 322, as described in further detail hereinbelow.

Referring back to FIG. 3A, the flow meter apparatus 3000 furtherincludes a processor 330, in communication with the magnetic fieldsensors 321, 322.

Optionally, the processor 330 is embedded in an electric circuit, on adigital processing board, as described in further detail hereinabove.

The processor 330 calculates a parameter which characterizes the flowingof the substance through the conduit, using changes in the signalsgenerated by the sensors 321, 322, as described in further detailhereinbelow.

The signals generated by the sensors 321, 322 are indicative of thedirections of the magnetic fields. Consequently, the changes in thesignals are indicative of changes in direction of the magnetic fields inthe positions in which the sensors 321, 322 are deployed, as describedin further detail hereinbelow.

As the magnets 311, 312 rotate, the magnetic field sensed by each of thesensors 321, 322 alternates between different magnetic polaritydirections, with a ninety degrees phase difference between the sensors321, 322, as described in further detail hereinbelow.

Consequently, the processor 330 processes the signals generated by thesensors 321, 322, to calculate a parameter which characterizes the flowof the substance through the conduit.

The calculated parameter may include, but is not limited to: velocity offlowing of the substance through the conduit, volume of the substancewhich flows through the conduit, direction of flow of the substancethrough the conduit, etc.

Optionally, each of the two magnetic field sensors 321, 322, generates afirst signal when the magnetic field is a magnetic field of a firstdirection, with an intensity which is greater than a first threshold.The sensor's signal remains the same (i.e. the generated first signal),until the magnetic field turns into a magnetic field of an oppositedirection, with an intensity greater than a second threshold, asdescribed in further detail hereinbelow.

In one example, each of the two sensors 321, 322, is a Hall-effectdigital latch connected to the processor 330 through a channel of anelectric circuit board on which the processor 330 is implemented.

Optionally, each latch samples (i.e. senses) the intensity and directionof the magnetic field in the position in which the latch is deployed, ina periodic basis.

Optionally, the processor 330 controls the sensors 321, 322 (i.e.latches), by dynamically adjusting a frequency rate in which each of thesensors 321, 322 samples the direction and strength of magnetic field inthe sensor's position.

In the example, every two seconds, the processor 330 instructs thesensors 321, 322 to sample the magnetic fields. When the velocity ofsubstance flow increases, the processor 330 increases the frequency inwhich the processor 330 instructs the sensors 321, 322 to sample themagnetic fields.

By adjusting the frequency of the sampling, the processor 330 may saveelectric power consumption by the sensors 321, 322, and extend thesensors' 321, 322 life expectancy, as described in further detailhereinbelow.

The Hall-effect digital latch switches on only when the latch senses asouth magnetic field of an intensity greater than a first threshold (aspredefined by the latch vendor), in which case, the channel transmits apositive signal (say a ‘1’ bit) from the latch, to the processor 330.

In the example, the switched on Hall-effect digital latch switches offonly when the magnetic field turns into a north magnetic field of anintensity greater than a second threshold (as predefined by the latchvendor). That is to say that once turned on, the latch remains turned onand the signal remains positive, until the latch senses a north magneticfield of intensity greater than the second threshold.

When the latch switches off, the channel which connects the latch to theprocessor 330 transmits a negative signal (say a ‘0’ bit) from thelatch, to the processor 330, as described in further detail hereinbelow.

The two thresholds may be the same (only with a magnetic field inopposite direction), as described in further detail hereinbelow.

In every instant of time of operation of the apparatus 3000, each of thetwo channels (one channel for each sensor), carries a signal (i.e. a ‘0’bit or a ‘1’ bit), which depends on the status (switched on or switchedoff) of the latch connected to the channel.

Optionally, the processor 330 calculates the parameter, using a stack(i.e. a last-in first-out data structure, as known in the art) ofsignals or another data structure, as known in the art. The stackaccumulates the signals transmitted from each of the sensors 321, 322.

Upon a change (also refereed to hereinbelow as an interrupt) in signalof one of the sensors 321, 322 (i.e. latches), the processor 330 samplesthe two channels which transmit the signals from the sensors 321, 322 tothe processor 330, reads the pair of signals from the channels, andpushes the pair of signals read from the channels into the stack.

Every few seconds, or immediately upon the interrupt, the processor 330processes the signals accumulated in the stack, for calculating theparameter which characterizes the flow of the substance through theconduit, and empties the stack.

Changes in the pairs of signals reflect the changing (i.e. rotating)positions of the magnets 311, 312, and are thus indicative of the flowof the substance through the conduit.

In one example, the pair of signals read (say when the magnets 311, 312are in the positions illustrated using FIG. 3B) is ‘01’, where the firstsensor 321 (say latch) generates the negative signal (‘0’) and thesecond sensor 322 (positioned above magnet 312) generates the positivesignal (‘1’).

When the magnets 311, 312 rotate clockwise, along the circle, into aposition which is illustrated using FIG. 3C, the pair of signals read is‘11’, where the first sensor 321 now positioned over magnet 312,generates the positive signal (‘1’) and the second sensor 322 remainswith a positive signal (‘1’).

When the magnets 311, 312 rotate further, clockwise, along the circle,into a position which is illustrated using FIG. 3D, the pair of signalsread is ‘10’, where the first sensor 321 keeps the positive signal (‘1’)and the second sensor 322, now positioned over magnet 311, switches to anegative signal (‘0’).

Consequently, the processor 330 interprets a signal sequence of ‘011110’as indicative of a clockwise rotation of the magnets through the stagesillustrated using FIG. 3B to 3D (i.e. a 270° clockwise rotation of thewheel 315).

Similarly, the processor 330 interprets a signal sequence of ‘011101’ asindicative of a rotation in opposite direction, through the stagesillustrated using FIG. 3D to 3B (i.e. a 270° counterclockwise rotationof the wheel 315).

Taking into consideration interpretation of the sequence of signals,together with calibration data which correlates the velocity of therotation and volume of substance, the processor 330 calculates theparameter which characterizes the flow of the substance through theconduit (say the flow rate in terms of volume and time).

Optionally, the calibration data is obtained through an initial stage inwhich the apparatus 3000 is calibrated, as known in the art.

Optionally, the processor 330 further takes into consideration data on atime interval of the rotation indicated by the signal sequence, say fromthe processor's 330 own clock, for calculating the parameter.

Optionally, the processor 330 further uses a statistical model forfiltering out parameter values which deviate from a standard deviationbased interval, as known in the art.

Optionally, the processor 330, as well the magnets 311, 312 and thesensors 321, 322 may be removed from the apparatus 3000, for repair,routine maintenance, replacement, etc.

Reference is now made to FIG. 4A, which is a block diagram schematicallyillustrating a fourth flow meter apparatus, according to an exemplaryembodiment of the present invention.

A flow meter apparatus 4000 according to an exemplary embodiment of thepresent invention includes the two magnets 311, 312 of apparatus 3000,as described in further detail hereinbelow, and illustrated using FIGS.5A and 5B.

The apparatus 4000 further includes the mechanical element 315, to whichthe magnets 311, 312 are mechanically coupled, as described in furtherdetail hereinabove. The mechanical element 315 is a rotational elementsuch as a wheel connected to a rotatable shaft 318, as described infurther detail hereinabove.

However, the apparatus 4000 includes three magnetic fields sensors 421,422 and 423, rather than the two sensors of apparatus 3000.

As schematically illustrated using FIG. 4B, each of the sensors 421-423,is deployed in a respective position over a point in circumference ofthe circle, on which the magnets 311, 312 rotate. The points form twoangles of about sixty degrees with an axis of the magnets' 311, 312rotation.

As the magnets 311, 312 rotate, the magnetic field sensed by each of thesensors 421-423 alternates between different magnetic polaritydirections, with a phase difference between the sensors 421-423, asdescribed in further detail hereinabove.

The apparatus 4000 further includes a processor 430, which processes thesignals generated by the sensors 421-423, to calculate a parameter whichcharacterizes the flow of the substance through the conduit, say avelocity or a volume, as described in further detail hereinabove.

Reference is now made to FIG. 5A, which is a block diagram schematicallyillustrating an exemplary pair of opposite magnets, in a top view,according to an exemplary embodiment of the present invention.

A pair of magnets 311, 312 according to an exemplary embodiment of thepresent invention, includes two halves which form a ring.

The two magnets 311, 312 which form the ring, are polarized in oppositedirections, or in nearly opposite directions. More specifically, onehalf 311 of the ring is a magnet with a north magnetic pole up and asouth magnetic pole down, whereas another half 312 of the ring is amagnet with a south magnetic pole up and a north magnetic field down.

When coupled to a mechanical element which rotates about a shaft uponflowing of a substance through a conduit, say when fastened to theshaft's circumference, the magnets 311, 312 rotate with the shaft.

Consequently, magnetic field sensors carefully positioned above a planein which the mechanical element rotates, sense a magnetic field whichalternates as the mechanical element rotates upon flowing of thesubstance through the conduit, as described in further detailhereinabove.

Further, the two halves 311, 312 (i.e. magnets) are attracted to eachother, thus avoiding a need to use fasteners to connect the two halves.Consequently, a manufacturing processing of apparatus 2000 may becomemore efficient and less costly.

Optionally, the ring formed by the two magnets 311, 312 fits the shaft318 circumference. Consequently, the magnets 311, 312 may beconveniently installed on circumference of the shaft 318, for rotationwith the shaft 318 and the wheel 315.

Reference is now made to FIG. 5B, which is a block diagram schematicallyillustrating an exemplary pair of opposite magnets, in a cross-sectionalview, according to an exemplary embodiment of the present invention.

Looking at the ring comprised of the two halves 311, 312, in across-sectional view, one half 311 is a magnet with a north magneticpole up and a south magnetic pole down, whereas the second half 312 ofthe ring is a magnet with a south magnetic pole up and a north magneticfield down.

Reference is now made to FIG. 6, which is a flowchart schematicallyillustrating a flow metering method, according to an exemplaryembodiment of the present invention.

In an exemplary method, two or more magnets polarized in opposite (ornearly opposite) directions, are mechanically coupled 610 to amechanical element.

The mechanical element is mounted in a flow conduit and is movable by asubstance flowing through the flow conduit, for imparting movement fromthe mechanical element to the magnets, as described in further detailhereinabove.

The movement of the mechanical element may be, but is not limited to: arotational movement, a lateral movement, an irregular movement, etc., asknown in the art.

In one example, the magnets are installed 610, mechanically coupled tothe mechanical element, in substantially opposite polarizationdirections, say one magnet with a north pole up and a south pole down,and one magnet with a south pole up and a north pole down.

The magnets may be affixed to the mechanical element using glue,fasteners (say screws), etc., as described in further detailhereinbelow.

The exemplary method further includes a step of deploying 620 two ormore magnetic field sensors.

Each of the sensors is deployed in a respective position next to themagnets, say in a distance of 1 to 20 millimeter from the magnets. Thesensor senses a direction of a magnetic field in the position, andgenerates a signal indicative of the direction.

Then, the sensor deployed in each of the positions is used to sense 625a direction of a magnetic field in the position and generate a signalindicative of the direction.

Optionally, each of the magnetic field sensors generates a first signalupon the magnetic field being a magnetic field of a first direction,with an intensity which is greater than a first threshold. The sensor'ssignal remains the same (i.e. the generated first signal), until themagnetic field turns into a magnetic field of an opposite direction,with an intensity which is greater than a second threshold, as describedin further detail hereinbelow.

In one example, each of the sensors is a Hall-effect digital latch whichswitches on only when the latch senses a south magnetic field of anintensity greater than a first threshold (as predefined by the latchvendor).

In the example, the switched on Hall-effect digital latch switches offonly when the magnetic field turns into a north magnetic field of anintensity greater than a second threshold (as predefined by the latchvendor), as described in further detail hereinbelow. That is to say thatthe once turned on, the latch remains turned on, until the latch sensesa north magnetic field of an intensity greater than the secondthreshold.

The two thresholds may be the same (only with a magnetic field inopposite direction), as described in further detail hereinbelow.

Optionally, the sensors are distributed in an asymmetric manner over acircle in which the sensors rotate, as described in further detail andillustrated hereinabove, using FIGS. 3A-3B and 4A-4B.

In a first example, there are deployed 620 the two sensors 321, 322, asdescribed in further detail hereinabove, and illustrated using FIG.3A-3B.

Each one of the sensors 321, 322 is deployed in a respective positionover a point in circumference of the circle. The points form an angle ofabout ninety degrees with an axis of the magnets' rotation, as describedin further detail hereinabove.

As the magnets 311, 312 rotate below the sensors 321, 322, the magneticfield sensed by each of the sensors 321, 322 alternates betweendifferent magnetic polarity directions, as described in further detailhereinbelow.

In a second example, the magnets 311, 312 also rotate in a circle in aplane below the magnetic field sensors.

However, in the second example, there are installed three sensors421-423, as described in further detail hereinabove, and illustratedusing FIG. 4A-4B.

Each one of the sensors 421-423 is deployed in a respective positionover a point in circumference of the circle. Each two adjacent ones ofthe points form an angle of about sixty degrees with an axis of rotationof the magnets 311, 312, as described in further detail hereinbelow.

Next, there may be calculated 630 a parameter which characterizes theflowing of the substance through the conduit, say using changes in thesignals generated by the sensors, as described in further detailhereinbelow. Optionally, the parameter is calculated by the processor330, as describe in further detail hereinabove.

As the signals generated by the sensors are indicative of the directionsof the magnetic fields, the changes in the signals are indicative ofchanges in direction of the magnetic fields, as described in furtherdetail hereinbelow.

Optionally, the strength and direction of the magnetic field in each ofthe sensor's positions are sampled in a dynamically adjusted frequencyrate.

For example, the processor 330 may control the sensors 321, 322, bydynamically adjusting a frequency rate in which each of the sensors 321,322 samples the direction and strength of magnetic field in the sensor's321, 322 position, and re-generate (i.e. update) the signal.

In the example, every two seconds, the processor 330 instructs thesensors 321, 322 to sample the magnetic field. When the velocity ofsubstance flow increases, the processor 330 increases the frequency inwhich the processor 330 instructs the sensors 321, 322 to sample themagnetic field.

By adjusting the frequency of the sampling, the processor 330 may saveelectric power consumption by the sensors 321, 322, and extend thesensors' 321, 322 life expectancy, as described in further detailhereinbelow.

The calculated parameter may include, but is not limited to: velocity offlowing of the substance through the conduit, volume of the substancewhich flows through the conduit, direction of flow of the substancethrough the conduit, etc., as described in further detail hereinbelow.

In one example, the mechanical element is a wheel (say a rotor withblades), as described in further detail hereinabove. The mechanicalelement is set in path of the material (say a fluid or a gas) whichflows through the flow conduit. As the material flows through theconduit, the material sets the rotor in rotational motion, as known inthe art. Consequently, the magnets mechanically coupled to themechanical element, rotate with the element, as described in furtherdetail hereinabove.

In the example, the magnets are mounted on the mechanical element (saythe rotor) and rotate simultaneously with the mechanical element. Thedirection of the magnetic field sensed by each of the sensors,alternates in concert with rotation of the magnets, as described infurther detail hereinbelow.

The mechanical element may also have any of other known in the artforms, usable for generation of movement by a substance, when thesubstance flows through a flow conduit. The mechanical element mayinclude, but is not limited to any element currently used in mechanicalflow meters, such as turbines of various designs, Woltmann meters,pressure-based meters, etc.

Reference is now made to FIG. 7, which is a graph illustrating concertedchanges in a sensor signal and in a magnetic field, according to anexemplary embodiment of the present invention.

An exemplary sinusoidal graph 711 depicts a magnetic fields intensityand direction, in a position of sensor 322 (say the Hall effect latch)deployed over the circle in which the magnets 311, 312 of apparatus 3000rotate, as described in further detail and illustrated using FIGS. 3Aand 3B hereinabove.

Graph 712 depicts the signal generated by the sensor 322. The signalchanges simultaneously with the changes in intensity and direction ofthe magnetic field, as the magnets 311, 312 rotate with the mechanicalelement 315 of the apparatus 3000.

When the sensor 322 senses a magnetic field in a first direction, withan intensity greater than a first threshold (denoted: t1), say when themagnets align in the position illustrated using FIG. 3B hereinabove, thesensor 322 generates a positive (‘1’ bit) signal.

The signal remains positive, until the magnetic field is in an oppositedirection, with an intensity greater than a second threshold (denoted:t2), as described in further detail hereinbelow, in which point, thesensor 322 generates a negative (‘0’ bit) signal.

The signal turns positive again only when the magnetic field is back inthe first direction and has a magnetic field intensity greater than thefirst threshold (denoted: t1).

As shown using the graph 712, the changes in the signal through rotationof the magnets 311, 312 take place in fixed or nearly fixed frequency.That is to say that the time interval between interrupts (i.e. changes)in which the signal changes from negative (say a ‘0’ bit) to positive(say a ‘1’ bit) or vice versa, remains the same (or nearly the same).

The frequency remains the same (or nearly the same), even when themagnets 311, 312 are placed in further distance from the sensor 322 (orif the magnets are replaced by weaker magnets), as long as the magneticfields are strong enough to be sensed by the sensor 322.

For example, an exemplary sinusoidal graph 751 depicts a weak magneticfield's intensity and direction, in a position of the sensor 322 (saythe Hall effect latch) deployed over the circle in which the magnets311, 312 of apparatus 3000 rotate, as described in further detail andillustrated using FIG. 3A hereinabove.

As shown using the graph 752, the changes in the signal through rotationof the magnets 311, 312 take place in the same fixed or nearly fixedfrequency, although with a slight time displacement of the graph 752.

With the fixed frequency of signal changes (i.e. interrupts), thesampling of the magnetic field by the sensor 322 may take place in asomewhat relaxed manner (i.e. less frequently). Consequently, there maybe saved electric power consumption by the sensor 322 and there may beprovided a longer life expectancy for the sensor 322.

Consequently, when the magnets 311, 312 rotate in a circle under thesensors 321, 322, the resultant signal may experience symmetricalsequence of interrupts, with a fifty percent duty cycle, as known in theart.

By contrast, in a different setting, a sensor of a second type generatesa positive signal only when the intensity of the magnetic field in anydirection (south or north) is stronger than the respective threshold (t1or t2), and a negative signal in between.

The second type sensor is deployed in a point above a single magnetrotating in circle below the second type sensor.

The signal of the second type sensor changes in a changing frequency.That is to say that the time interval between interrupts (i.e. changes)in which the signal changes from negative (say a ‘0’ bit) to positive(say a ‘1’ bit) and vice versa are different, as illustrated usinggraphs 731 and 732 hereinbelow.

Sinusoidal graph 731 depicts a magnetic fields intensity and direction,in a position of the second type sensor when the magnet rotates.

Graph 732 depicts the signal generated by the second type sensor,through the rotation of the magnet.

Further to the difference in the time interval between the interrupts,the frequency when using a sensor of the second type is much moredependent on the strength of the signal magnet which rotates below thesecond type sensor.

For example, graph 782 depicts the signal generated by the second typesensor when the magnet is replaced by a slightly weaker magnet, whereasexemplary sinusoidal graph 781 depicts the changes in the weakermagnets' field as sensed by the second type sensor.

Reference is now made to FIG. 8, which is a block diagram schematicallyillustrating a flow meter kit, according to an exemplary embodiment ofthe present invention.

An exemplary flow meter kit, according to an exemplary embodiment of thepresent invention, includes a processor 830 (say a processor 830embedded in an electric circuit), which may be installed in a pipeline,as described in further detail hereinabove.

The processor 830 may communicate with two or more magnetic fieldsensors and calculate a parameter which characterizes flowing of asubstance through a flow conduit, as described in further detailhereinabove.

More specifically, the processor 830 calculates the parameter, usingchanges in a signal generated by each respective one of the sensors. Thesignal is indicative of a direction of a magnetic field in position ofthe sensor, as described in further detail hereinabove.

The calculated parameter may include, but is not limited to: velocity offlowing of the substance through the conduit, volume of the substancewhich flows through the conduit, direction of flow of the substancethrough the conduit, etc.

The magnetic field is produced by two or more magnets mechanicallycoupled to a mechanical element (say a rotor or a turbine) mounted inthe flow conduit, in substantially opposite polarization directions, asdescribed in further detail hereinabove.

When a substance flows through the conduit, the substance moves themechanical element, say by setting the rotor or turbine in rotation, asdescribed in further detail hereinabove.

Optionally, the exemplary flow meter kit further includes the magnets810, for mechanical coupling to the mechanical element, say using glueor fasteners (say screws).

The magnets 810 need to be coupled to the mechanical element, with themagnets' polarity oriented in substantially opposite directions (say onemagnet with a north pole up and another magnet with a south pole up), asdescribed in further detail hereinabove.

Optionally, the exemplary flow meter kit further includes the sensors820, for deployment in positions next to the magnets, using glue orfasteners (say screws).

The sensors 820 need to be deployed in a predefined spatial relation tothe magnets 810, say a relation similar to the one described in furtherdetail hereinabove, using FIGS. 3A and 3B hereinabove.

Optionally, the mechanical element is an element of one of manycurrently used mechanical metering devices, such as the meters currentlyused for measurement of water, gas, etc.

The processor 830, as well the magnets 810 and the sensors 820, may beremoved from the mechanical metering device, for repair, routinemaintenance, replacement, etc.

In one example, the mechanical element is a rotor connected to arotatable shaft, with rotor vanes extending radially, at an angle ofinclination with the rotor's axis (i.e. the shaft), etc., as describedin further detail hereinabove.

The rotor is set in path of a material (say a fluid or a gas) whichflows through a flow conduit. As the material flows through the conduit,the material impinges on the vanes and imparts a force to the vanes'surfaces, thus setting the rotor in rotational motion, as known in theart. Consequently, the magnets 810 mechanically coupled to the rotorrotate with the rotor, and each of the sensors 820 deployed over themagnets 810, senses a magnetic field which changes as the magnets 810rotate, as described in further detail hereinabove.

The mechanical element may also have any of other known in the artforms, usable for generation of movement by a material flowing through aflow conduit, as currently used for mechanical flow measurement, such asturbines of various designs, Woltmann meters, pressure-based meters,etc.

Optionally, each of the magnetic field sensors 820 generates a firstsignal upon the magnetic field being a magnetic field of a firstdirection, with an intensity which is greater than a first threshold.The sensor's signal remains the same (i.e. the generated first signal),until the magnetic field turns into a magnetic field of an oppositedirection, with an intensity which is greater than a second threshold,as described in further detail hereinbelow.

In one example, each of the sensors 820 is a Hall-effect digital latchwhich switches on only when the latch senses a south magnetic field ofan intensity greater than a first threshold (as predefined by the latchvendor).

In the example, the switched on Hall-effect digital latch switches offonly when the magnetic field turns into a north magnetic field of anintensity greater than a second threshold (as predefined by the latchvendor), as described in further detail hereinbelow. That is to say thatonce turned on, the latch remains turned on, until the latch senses anorth magnetic field of intensity greater than the second threshold.

The two thresholds may be the same (only with a magnetic field inopposite direction), as described in further detail hereinbelow.

It is expected that during the life of this patent many relevant devicesand systems will be developed and the scope of the terms herein,particularly of the terms “Flow Meter”, “Magnet”, “Permanent magnets”,“Magnets of grade N45”, “electromagnets”, “Sensor”, “Hall effect latch”,“Processor”, “Electric circuit”, “digital processing board”, “Turbine”,“Rotor”, and “Mechanical flow meter”, is intended to include all suchnew technologies a priori.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable subcombination.

Although the invention has been described in conjunction with specificembodiments thereof, it is evident that many alternatives, modificationsand variations will be apparent to those skilled in the art.Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims.

All publications, patents and patent applications mentioned in thisspecification are herein incorporated in their entirety by referenceinto the specification, to the same extent as if each individualpublication, patent or patent application was specifically andindividually indicated to be incorporated herein by reference. Inaddition, citation or identification of any reference in thisapplication shall not be construed as an admission that such referenceis available as prior art to the present invention.

What is claimed is:
 1. A conduit flow meter apparatus comprising: atleast two magnets polarized in substantially opposite directions,mechanically coupled to a mechanical element mounted in a flow conduitand movable by a substance flowing through the flow conduit, forimparting movement from the mechanical element to said magnets; and atleast two magnetic field sensors, each of said sensors deployed in arespective position next to said magnets, configured to sense adirection of a magnetic field in said position and to generate a signalindicative of said direction.
 2. The flow meter apparatus of claim 1,further comprising a processor, in communication with said magneticfield sensors, configured to calculate a parameter characterizing theflowing of the substance through the conduit, using changes in saidgenerated signals.
 3. The flow meter apparatus of claim 1, wherein saidmagnets rotate in a circle, said magnetic field sensors comprise twosensors, and each one of said sensors is deployed in a respectiveposition over a point in circumference of the circle, the points formingan angle of about 90 degrees with an axis of rotation of said magnets.4. The flow meter apparatus of claim 1, wherein said magnets rotate in acircle, said magnetic field sensors comprise three sensors, and each oneof said sensors is deployed in a respective position over a point incircumference of the circle, each two adjacent ones of the pointsforming an angle of about 60 degrees with an axis of rotation of saidmagnets.
 5. The flow meter apparatus of claim 1, wherein said magnetsrotate in a circle and said magnetic field sensors are distributedasymmetrically over the circle.
 6. The flow meter apparatus of claim 1,wherein at least one of the sensors is further configured to sense anintensity of the magnetic field in said position of said sensor.
 7. Theflow meter apparatus of claim 2, wherein the processor is furtherconfigured to control said sensor, for dynamically adjusting a frequencyrate in which said sensor samples the magnetic field and re-generatesthe signal.
 8. The flow meter apparatus of claim 2, wherein thecalculated parameter characterizing the flowing of the substance throughthe conduit is a velocity of flowing of the substance through theconduit.
 9. The flow meter apparatus of claim 2, wherein the calculatedparameter characterizing the flowing of the substance through theconduit is a volume of the substance flowing through the conduit. 10.The flow meter apparatus of claim 2, wherein the calculated parametercharacterizing the flowing of the substance through the conduit is adirection of flow of the substance through the conduit.
 11. A method forconduit flow metering, comprising the steps of: a) installing at leasttwo magnets polarized in substantially opposite directions in a flowconduit, by mechanically coupling said magnets to a mechanical elementmounted in the flow conduit and movable by a substance flowing throughthe flow conduit, for imparting movement from said mechanical element tosaid magnets; b) deploying at least two magnetic field sensors, eachsensor being deployed in a respective position next to said magnets; andc) sensing a direction of a magnetic field in each of the positions,using the sensor deployed in the position.
 12. The method of claim 11,further comprising a step of calculating a parameter characterizing theflowing of the substance through the conduit, using changes in saidsensed directions.
 13. The method of claim 11, wherein said magnetsrotate in a circle, said magnetic field sensors comprise two sensors,and each one of said sensors is deployed in a respective position over apoint in circumference of the circle, the points forming an angle ofabout 90 degrees with an axis of rotation of said magnets.
 14. Themethod of claim 11, wherein said magnets rotate in a circle, saidmagnetic field sensors comprise three sensors, and each one of saidsensors is deployed in a respective position over a point incircumference of the circle, each two adjacent ones of the pointsforming an angle of about 60 degrees with an axis of rotation of saidmagnets.
 15. The method of claim 11, wherein said magnets rotate in acircle and said magnetic field sensors are distributed asymmetricallyover the circle.
 16. The method of claim 11, further comprising sensingof intensity of the magnetic field in position of the sensor.
 17. Aconduit flow meter kit, comprising: a processor, configured tocommunicate with at least two magnetic field sensors and calculate aparameter characterizing flowing of a substance through a flow conduit,using changes in a signal generated by each respective one of thesensors, the signal being indicative of a direction of a magnetic fieldin position of the sensor, the magnetic field being produced by at leasttwo magnets polarized in substantially opposite directions andmechanically coupled to a mechanical element mounted in the flow conduitand movable by the substance flowing through the flow conduit, forimparting movement from the mechanical element to the magnets.
 18. Theflow meter kit of claim 17, further comprising said magnets, formechanical coupling to the mechanical element, with polarity insubstantially opposite directions.
 19. The flow meter kit of claim 17,further comprising said sensors, for deployment in the positions, in apredefined spatial relation to the magnets.
 20. The flow meter kit ofclaim 17, wherein the signal is further indicative of intensity of themagnetic field in position of the sensor.